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»EtH» An Eskimo Brain 



-^ BY 

ALES HRDLICKA, M.D. 

NEW YORK 



THE KNICKERBOCKER PRESS 

NEW YORK 

1901 




Class. 
Book 



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An Eskimo Brain 



BY 

ALES HRDLICKA, M.D. 

NEW YORK 



THE KNICKERBOCKER PRESS 

NEW YORK 

19OI 



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KISHU AND MENEE (PHOTOGRAPHED ON THEIR ADMISSION TO BELLEVUE HOSPITAL) 



AN ESKIMO BRAIN 
By ales HRDLICKA 

The brain in question ' is that of Kishu (or Kissuk), an adult 
male Eskimo of about forty-five years of age, who died of acute 
general tuberculosis.'' Kishu was a chief of his tribe ; he meas- 
ured 1.64 m. in height, weighed about 170 lbs., was muscular, 
and in every respect normally developed. He died at Bellevue 
Hospital within less than five months after the inception of his 
disease. Plate XIII shows him (together with his son) as he ap- 
peared on admission to the hospital. 

The autopsy was performed in my presence by Dr Harlow 
Brooks. I am indebted to Dr Brooks for notes concerning the 
general condition of the brain and its membranes, and to the 
authorities of Bellevue hospital and the American Museum of 
Natural History for the privilege of examining the specimen. 
Before the skull was opened, I obtained the following measure- 
ments of the head : 

Diam. antero-post. max 19.8 cm. 

Diam. lateral max 1 5. 1 cm. 



^ The specimen was examined in i8q6 and reexamined in igoi. A preliminary 
report on it was published by the author in the Proceedings of the Amer. Medico- 
Psychological Assoc, 1899, and a full report in the American Anthropologist, 
N. s., 3, 1901. 

^ Kishu was one of the six Eskimo who were brought to New York in 1896 by 
Lieutenant Peary, from the neighborhood of Smith sound. Of these six Eskimo, 
four, including Kishu, have since succumbed to acute tuberculosis ; one was sent back 
to Smith sound, and a boy of about twelve years survives, after having recovered from 
incipient pulmonary tuberculosis, in the care of Mr Wallace, the former Superintend- 
ent of the American Museum of Natural History. The brains of the three other 
Eskimo who died, as well as an additional specimen, — the brain of an Eskimo girl 
from Alaska, — will be reported upon in detail by Mr Edward A. Spitzka, of Columbia 
College. Some measurements and observations which I have made of these brains 
will be included, for comparison, in this paper. 

3 



4 AN ESKIMO BRAIN 

(Cephalic index 76.26.) 
Height (from Hne joining the aud. naeati to 

bregma) about 14.2 cm. 

Circumference maximum of the head 56.8 cm. 

Diam. biauricular (between the depressions 
over the roots of zygomae, in front of 

the ear) 13.2 cm. 

Diam. frontal minimum 10.4 cm. 

Diam. bigonial 1 1 . i cm. 

Diam. bizygomatic max 14.5 cm. 

Height of face : chin to nasion 12.3 cm. 

chin to interciliary line 14.3 cm. 

chin to insertion of hair 20.0 cm. 

These measurements agree in the main with those which I 
made of the other Eskimo from the same locality, thus showing 
that Kishu was not racially exceptional. 

The scalp was found to be less than the average in thickness ; 
this was undoubtedly due to advanced general emaciation. The 
skull was entirely symmetrical ; the sutures mostly still pervious ; 
skull-cap thin. No adhesion of the dura ; the soft membranes 
normal. Several masses of Pacchionian granulations over the 
longitudinal sinus. No signs of tuberculosis/ nor any other 
pathological lesion, within the cranial cavity. Very small quan- 
tity of fluid. There was a pronounced pigmentation of the pia 
and arachnoid from the pons to over and below the calamus 
scriptorius. 

Weight of brain, denuded of dura mater, after a few minutes' 
exposure for drain, 1503 grammes." The specimen was laid in 
20 parts 5 % formaline and 80 parts 95 % alcohol. 



' The brain and the heart were about the only organs in which no tubercular lesions 
were found. 

2 Mean weight of white male brain in 154 men of mean height of 1.680 m. equals 
1361.5 grams (Broca) ; mean weight of white male brain in 168 men of mean height 
of 1.679 "^- equals 1357.5 grams (Manouvrier). 



AN ESKIMO BRAIN 5 

Examination of the Brain 

(Three weeks after death) 

Weight 

The brain and its principal parts, denuded of the membranes, 
weigh, after 15 minutes' drainage, as follows : 

Whole encephalon 1325.0 gr. 

(Loss in three weeks through solution and 

through loss of membranes 178.0 gr.) 

Cerebrum. ....... 1155.0 gr. or 87.17^ of the total. 

Right hemisphere ... 577.0 gr. 

Left hemisphere 5/8.0 gr. 

Cerebellum 142.0 gr. or 10.72 % of the total. 

Pons and bulb 28.0 gr. or 2. i % of the total. 

The proportions of the cerebrum and cerebellum to the whole 
brain are very nearly like those of whites,^ but the relative weight 
of the pons and bulb is slightly greater. 

GENERAL OBSERVATIONS 

Cerebrum 

The hemispheres in general are very well developed. The 
gyration is pronounced and rather more complex than that 
found on the brains of average whites. The principal sulci are 
deep. The thickness of the gray matter shows no appreciable 
difference from that observed in the brains of whites. The gyra- 
tion of the left hemisphere is perceptibly more complex, particu- 
larly in the frontal lobes, than that of the right. A striking 
feature is the predominance on both hemispheres, but more espe- 
cially on the right, of vertical gyration. 



^ In the white brain, the proportionate weight of the cerebellum, medulla, and 
pons together is to that of the whole brain in the adult as 13 to 87 (Huschke). The 
cerebellum is 10.7 of the total encephalon (Meynert). According to Broca, the rela- 
tive M'eights to that of the whole encephalon are : cerebrum, 87.3 ^ ; cerebellum, 10.6 %\ 
pons and bulb, i.gi %. As to the hemisphere, in 264 men Broca found the right to 
be the heavier in 138 cases, the left in 105 cases ; the weight was even in 21 cases. 



O AN ESKIMO BRAIN 

The hemispheres show certain gross and many small asym- 
metries. The principal of the gross asymmetries are the differ- 
ences in the limbic, temporo-sphenoidal, and occipital lobes. All 
these, as well as the minor peculiarities of the brain, will be 
described later. 

Norma Superior. — Viewed from above, the cerebrum is dis- 
tinctly hexagonal in its outline. The longest sides of the hexagon 
are the antero-lateral lines, upon which follow, in the order 
named, the anterior, the postero-lateral, and the posterior lines. 
The outline of the frontal lobes is quite angular. 

The Norma Lateralis^ or the outline of the cerebrum when 
looked at from the side, is obliquely quadrilateral. The antero- 
inferior line (base of the frontal with the antero-inferior boundary 
of the temporal lobes), and the postero-inferior boundary (base 
of temporal and occipital lobes), are nearly straight. The two 
superior lines, moderately convex, meet over the precuneus. 

The right temporal lobe is perceptibly higher than the left. 

There are a few specially prominent points on the external 
surface of each hemisphere : on the left such points are the 
supramarginal and the second temporal gyri ; on the right, the 
supramarginal (somewhat less than on left), second temporal, and 
ascending parietal convolutions. 

Norina Ventralis, or the outline of the base of the hemi- 
spheres, is oval, almost square anteriorly and tapering posteriorly. 
The basal surface of the frontal lobes slopes toward the middle 
and there is a marked elevation on each frontal lobe along the 
median fissure. These elevations are somewhat larger than those 
found ordinarily in the brains of whites. The olfactory nerves 
run along their middle. Each of the elevations comprises ap- 
proximately two-sevenths of the base of each frontal lobe, and 
they, together with the sloping of the rest of the basal surfaces, 
impart to the inferior portion of the approximated frontal lobes a 
boat-keel-like appearance. 

Norma Anterior, — The outline of the anterior lobes forms 



AN ESKIMO BRAIN 7 

superiorly and laterally a regular arch, while inferiorly it consists 
of two shallow arches (concavities of the inferior surface of the 
frontal lobes), which meet over the median eminence. The 
outer terminal points of the arches are, as usual, situated higher 
than the inner ones. 

The anterior surface of the frontal lobes is almost vertical. 

Principal Measurements of the Cerebrum ^ 

Length maximum of left hemisphere 18.0 cm. 

Length maximum of right hemisphere 17.9 cm. 

Width maximum of cerebrum 13.6 cm,^ 

As to the parts situated at the base of the cerebrum, nothing 
unusual was found. The anterior perforated spaces are not 
appreciably larger than in whites. The optic commissure is well 
formed ; the optic nerves are strong. Hypophysis of ordinary 
size and appearance. Crura cerebri, cut at the niveau of the 
mesial border of the hippocampal gyri, are exactly equal in size. 
Their cross-section measures on each side 2.8 cm. in greatest 
length and 1.7 cm. in greatest width. 

There were no marked anomalies in the cerebral circulation. 
The ventricles were not opened. 

External Conformation of the Hemispheres 

PRINCIPAL sinuosities. FISSURE OF SYLVIUS 

The horizontal and ascending, or, more properly in this case, 
the anterior and posterior, branches of the presylvian begin sepa- 
rately, from the superior limiting sulcus of the insula on the 
right, and from a common fovea, connecting with that sulcus, on 
the left side.^ The anterior branch is in line with, and appears 
like a continuation of, the anterior limiting sulcus of the insula. 

^ For additional and comparative measurements, see the end of the paper. 

■^ By an oversight this measure was given in the preliminary report as 14.2 cm., 
which was incorrect. 

^ This, according to Cunningham, is also frequently the case in whites. In 
80 hemispheres examined by that author, two separate limbs of the presylvian were 
found 15 times (32.6 %) on the right and 15 times (44.1 f) on the left side. 

/ 



O ■ AN ESKIMO BRAIN 

Length of the anterior branch, 1., 2.8 cm., r., 2.6 cm. 
Length of the posterior branch, 1., 1.2 cm., r., 2.0 cm. 

On the left the posterior branch is very short, and on both 
sides the anterior branch is the longer (the reverse of that gen- 
erally found in white people). 

The anterior branch connects on the right, over a submerged 
but not deep gyrus, with a descending branch from the inferior 
frontal sulcus. 

The several important opercula situated along the lower 
border of the hemispheres in the neighborhood of these two an- 
terior branches of the Sylvian, differ somewhat in size and form. 
(See the description of the inferior frontal gyrus.) 

The stem or main limb of the Sylvian runs in a nearly 
straight line ; it measures, from the anterior branch of the pre- 
sylvian to the bifurcation, 6.5 cm. on the left and 5.2 cm. on the 
right hemisphere.^ 

The depth of the Sylvian fissure is considerable throughout. 
It measures : 

Left Right 

At the origin (x) of the anterior branches 3.0 cm. 3.1 cm. 

In middle between x and the precentral sulcus. ... 2.9 cm. 2.6 cm. 

Opposite the precentral sulcus 2.8 cm. 2.7 cm. 

The anterior branch of the presylvian measures at middle, 
left, 2.4 cm. ; right, 2.2 cm. Of the terminal branches of the 
Sylvian, the superior measures, left, 2.6 cm. ; right, 2.2 cm. The 
inferior measures, left, 1.8 cm. ; right, about 0.8 cm. in depth. 

The above figures show that, except at its beginning, the left 
Sylvian is the deeper at all points of measurement. 

The main limb of the Sylvian presents the following points of 
interest on the two sides of the brain : 

On the left, 0.5 cm. behind the posterior presylvian, there be- 
gins within the Sylvian, over a deep annectent loop, by means 

^ The left fissure is longer than the right one in the whites, and the disproportion 
"is evident at all points of growth" (Cunningham, Contr. to the Surf. Anat. of the 
Cerebr. Hemispheres^ 1892, p. 127 ; also Eberstaller). 



AN ESKIMO BRAIN 9 

of the diagonal sulcus, a pronounced, long, composite, vertical 
furrow, which runs nearly parallel with the central fissure and the 
precentral sulci, and terminates above not far from the superior 
border of the hemisphere. The sulcus shows a number of medium 
deep and deep annectent fascicles. 

On the right a similar furrow begins from the Sylvian, over a 
submerged loop, 0.6 cm. posteriorly to the hinder branch of the 
presylvian, and ascends in a quite straight line to within a few 
millimeters of the superior frontal sulcus. This furrow, in aver- 
age as well as at maximum, is deeper than that on the left 
(maximum depth on the right, 1.7 cm.). 

A little over i.o cm. posteriorly to the last mentioned furrow 
there begin from the Sylvian, on both sides, over a loop situated 
very deeply on the right and at medium depth on the left, the 
central fissures. 

The base of the ascending frontal gyrus shows on each side a 
small trans-precentral, the base of the ascending parietal convolu- 
tion a similar trans-postcentral sulcus. These sulci on the right side 
are entirely hidden in the Sylvian, but on the left side both reach 
to and slightly beyond the inferior border of the convolutions. 

Finally, 0.5 cm. anterior to the bifurcation on the right and 
almost at it on the left, the Sylvian connects on each side, over a 
submerged but quite superficial gyrus, with the united postcentral 
sulcus. 

The inferior lip of the Sylvian shows on the left the extremi- 
ties of four, on the right of three, transtemporal depressions. One 
of these furrows on the left and one on the right effect a shal- 
low communication with the superior temporal sulcus. 

Of the terminal branches of the Sylvian the superior is 2.4 cm. 
in length on the left, and 2.6 cm. on the right side ; they both 
end, as usual, in the supramarginal gyrus. The inferior ramus on 
the left runs 3.0 cm. horizontally and bifurcates ; one of its 
branches, 2.5 cm. long, passes upward into the angular gyrus, 
while the other, i.o cm. long, descends backward. On the right 



10 AN ESKIMO BRAIN 

the inferior terminal branch runs 1.5 cm. backward and down- 
ward and joins, over a deep gyrus, the first temporal sulcus. 

The superior terminal branch on the left makes two connec- 
tions : one, shallow, posteriorly, with a sulcus running downward 
and forward from the interparietal, and one, deeper, anteriorly, 
with a horizontal furrow running backward from the lower part 
of the postcentral sulcus. The inferior branch on the left con- 
nects, not far from the bifurcation, over a submerged annectent 
gyrus, with the posterior portion of the first temporal sulcus. 

On the right side the superior terminal branch of the Sylvian 
fissure is better developed than the inferior, and is deeper than 
the latter. It ascends for 2.0 cm. into the supramarginal gyrus, 
running parallel to the central fissure, and ends in a short T. 
The lower terminal branch descends for 1.3 cm., over two medium 
deep anastomotic fascicles, and joins the ascending ramus of the 
first temporal sulcus. 

An7iectent Gyri. — On the left a strong column, at medium 
depth, between parietal and temporal lobes, at the beginning of 
the lower terminal branch of the Sylvian. On the right a similar 
but more superficial column, at the beginning of the inferior 
branch, and another more posteriorly in the same. 

CENTRAL FISSURE 

Left Right 

Length (in a straight line, with 

sliding compass) 9.0 cm. (50 ^ of the total ^.(y cm. (48 <fo)} 

length of the 
hemisphere) 
Depth, maximum 2,3 cm. 2.5 cm. 

The fissure begins on both sides within the Sylvian, probably 
by means of the subcentral sulci of Eberstaller.'' The origin 



^ According to Schafer (Quain's ^?z«/., loth ed., ill, i, p. 143), " the length of 
the fissure in whites is about 2/5 (or 40 ^) of the whole length of the hemisphere. 
It is relatively longer and more curved in the anthropoid apes than in man." (See 
additional measurements.) 

'^ Cunningham (op. cit., 63) found a connection of the central and Sylvian in ig % 
of hemispheres (of whites) ; Benedict [Anat. Studien an Verbrecher-Gehirnen, 



PLATE II 




KISHU'S CEREBRUM (DORSAL ASPECT) 



AJV ESKIMO BRAIiV II 

of the central fissure is situated 0.6 cm. below the borders of the 
Sylvian on the left, and 1.5 cm. on the right It nearly connects 
on the right with the superior limiting sulcus of the insula. A 
short distance above the Sylvian border, the left central fissure 
shows a submerged, but not very deep, annectent gyrus; on the 
right there are two such fascicles in a similar location. 

The form of the central fissure is quite tortuous, especially on 
the right. The left fissure, neglecting minor bends, is, from 
above downward and with reference to the frontal lobe, convex, 
concave, convex, concave, much convex, and nearly straight ; 
that on the right, convex, concave, convex, concave, convex. 

Each of the fissures sends a number of incisures into the 
adjacent convolutions. On the right, 3.3 cm. above the Sylvian, 
the central fissure connects, over a quite superficial annectent 
gyrus, with the postcentral sulcus.* 

The two fissures show no submerged interruption. 

The superior ends of the central fissures are situated almost 
opposite ; distance from the same to the superior border, left, 0.5 
cm. ; right, 0.5 cm.^ 

Additional measures: 

Left Right 

(i) Origin of central fissure (on the fip of the Syl- 
vian) to frontal pole ^ 7.3 cm. 6.5 cm. 

{2) Superior extremity of central fissure to frontal 

pole 10.9 cm. 10.8 cm. 

Wien, 1872, p. 96) found a complete connection in 18 and an incomplete one in 6 of 
38 hemispheres examined. Giacomini ( Varieta d. circonvoluzioni cerebrali delV uomo, 
Torino, 1882, cited by Cunningham) found such a connection only in 21 among 336 
hemispheres. Retzius {Das Menschengehirn^ 1896, I, p. lOO) found the connection in 
23 % of the hemispheres of Swedes. 

^ Retzius observed, on the brains of whites, anastomosis of the Rolandic fissure 
with the inferior postcentral sulcus in 9 %, with the superior in 3 ^ of the cases. 

^ Cunningham (op. cit., p. 162), in 52 hemispheres of white children and adults, 
found the following conditions in this respect : "(a) In 60 % the upper end of the 
fissure cut the upper border of the hemisphere and appeared on the inner surface ; (b) 
in 21 ^ it just reached the upper border ; and (c) in 19 % it fell short of the upper 
border." 

'^ This and the following measures are the horizontal distances between vertical 
planes at the points mentioned. 



12 A.V ESKIMO BRAIN 

Left Right 

(3) Origin of central fissure to occipital pole. ., . 10.7 cm, 11.4 cm. 

(4) Superior extremity of central fissure to oc- 

cipital pole 7.1 cm. 7.1 cm. 

Reduced to per cent, of the total antero-posterior diameters 
of the hemispheres, these distances are : 

Left Right 

(i) 40-6 io z^.2i i 

(2) . 60.6 <fo 60.4 <fo 

(3) 59-4 i 63.7 io 

(4) 39-4 io 39-6 i 

PARIETO-OCCIPITAL FISSURE 

The fissure appears on both sides like a direct and equally deep 
continuation of the calcarine stem. It runs on each side, in nearly 
a straight line, upward and slightly backward to, and on the left 
2.1 cm., on the right 1.5 cm., over, the superior border of the 
hemisphere. The extremity forms on each side a small T, which 
is surrounded by a pronounced paroccipital gyrus. 

The average depth of the fissure is 2.3 cm. on the left and 2.3 
cm. on the right side ; its length, from its junction with the cal- 
carine stem to the superior border is on the left 4.0 cm., on the 
right 4.2 cm. 

The fissure on the left connects over a submerged but quite 
superficial gyrus wit];i the sub-precuneal sulcus, while that on the 
right shows a slightly deeper connection with a sulcus from the 
cuneus. 

There are only a few very deep annectent bundles within 
each fissure. 

CALCARINE STEM AND SULCUS 

The stem is simple, its course on each side slightly wavy. Its 
length is 2.6 cm. on the left, 3.3 cm. on the right ; its average 
depth on both sides about 1.5 cm. ; at its junction with the pari- 
eto-occipital it equals the latter in depth. 

Both calcarine sulci communicate with the stem over a sub- 
merged but not very deep gyrus. The left sulcus is nearly 



AN ESKIMO BRAIN 1 3 

Straight ; the right one describes anteriorly a moderate curve. 
The sulcus on the left is free from connections and gives off but 
two small incisures ; that on the right connects superficially with 
a cuneal sulcus and sends from its curve a deep branch, i.o cm. 
long, downward to the basi-mesial border. 

The calcarine sulcus extends on both sides to the dorsal sur- 
face of the occipital lobe, and terminates in a small bifurca- 
tion. The most distal point is on the left 1.55 cm., on the right 
1.3 cm., in a straight line beyond the border of the hemisphere. 

The length of the calcarine sulcus from its junction with the 
stem to the border of the occipital lobe is 4.6 cm. on the left, 4.8 
cm. on the right side. It is on both sides much shallower than 
the stem. 

There are a number of connecting fasciculi within the two 
calcarine stems and sulci. On the left there is a deep bundle 
in about the middle of the stem and reaching from the base 
of the stem to the point of the cuneus ; there are also two bundles 
at medium depth behind the junction of the stem and the sulcus 
and passing from the gyrus lingualis to the cuneus ; and there is 
another fascicle of medium depth in the sulcus, about 2 cm. from 
the occipital border. On the right side we find similar annectent 
gyri in similar locations, but the bundle in the stem passes down- 
ward to the bottom and does not visibly reach the cuneus. 

COLLATERAL FISSURE 

This furrow is of considerable extent, particularly on the 
right. Its total length, in a straight line, is 8.15 cm. on the left, 
and 1 1.3 cm. on the right. 

The anterior termination of the fissure is on both sides free 
and simple ; it is distant from the pole of the temporal lobe on 
the left 5.7 cm., on the right 2.9 cm. 

On both sides, nearly in the line of continuation of the collat- 
eral fissure and incising the antero-mesial border of the temporal 
lobe, is found a well-developed fissura rhinica. This furrow is 



14 AN ESKIMO BRAIN 

particularly marked on the left side where the collateral is 
shorter. 

Posteriorly, the left collateral fissure terminates in a line about 
3 mm. from the border of the hemisphere, while on the right 
it reaches the border. Both of the fissures connect, each by a 
shallow sulcus, with the third temporal. 

Each collateral gives off several incisures. In the posterior 
half of both fissures are found, at medium depth, annectent 
bundles which pass between the fusiform and lingual lobules. 

CALLOSO-MARGINAL FISSURE 

The gyration on the mesial surface of this brain presents 
several very interesting modifications. The calloso-marginal is 
duplicated on the left and almost triplicated on the right side. 
The main fissure is on both sides throughout continuous and 
connects freely and deeply with the paracentral. It is on both 
sides doubled by a pronounced mesial frontal sulcus. This is 
deep and continuous on the left, more shallow and interrupted by 
an isthmus on the right. In addition the right callosal gyrus is 
traversed along its entire superior extent by a shallow, inter- 
rupted sulcus, which runs parallel with the calloso-marginal fissure 
and separates the surface of the callosal into two nearly equal 
superior and inferior portions. 

The left calloso marginal begins in a simple way below the 
genu of the callosum ; the right proceeds from a subrostral sulcus 
which curves about a lobule on the posterior extremity of the 
mesial portion of the frontal lobe. 

During its course, each of the calloso-marginal fissures gives off 
a few small branches or incisures. On the left, as well as on the 
right, four such small branches indent the superimposed part of 
the superior frontal gyrus. 

There is on both sides a well-developed rostral, and on the 
right also a transverse subrostral sulcus ; there is also a fair repre- 
sentation on each side of the postlimbic sulcus. 



PLATE III 




KISHU^S CEREBRUM (BASA^ ASPECT) 



AN ESKIMO BRAIN I 5 

The paracentral sulci are well curved and both end on the 
dorsal surface of the hemisphere : the left in a line, 1.5 cm. from 
the median border and 0.7 cm. behind the superior extremity of 
the central fissure ; the right in a T, with the posterior branch 
much shorter than the anterior, 1.6 cm. from the median border 
of the hemisphere and 0.5 cm. behind the terminus of the central 
fissure. 

The average depth of the calloso-marginal is i.o cm. on the 
left, 1.3 cm. on the right ; that of the paracentral 1.5 cm. on the 
left and 1.8 cm. on the right side. 

Anjtectent Gyri. — There are in the calloso-marginal five or six 
deep bundles on the left and seven or eight such bundles on the 
right, passing between the callosal gyrus, the superior frontal 
convolution, and the paracentral lobule. 

MINOR FISSURES OR SULCI 

Frontal Lobe. — The superior frontal sulcus on the left is a con- 
tinuous furrow, which runs, in a tortuous way, from the anterior 
portion of the orbital surface to within a few millimeters of the 
superior precentral sulcus. On the right a similar but somewhat 
less tortuous furrow extends from the orbital border of the 
frontal lobe to the superior precentral sulcus, connecting with 
the same. 

Each of the sulci sends off a number of transverse branches 
and incisures. That on the left communicates with the medial 
frontal sulcus of Eberstaller and with the vertical furrow anterior 
to the precentral sulci ; that on the right connects with the 
medial frontal and the superior precentral sulcus. 

The depth of each of the superior frontal sulci averages about 
1.5 cm., the maximum depth measured being 2.8 cm. (on the 
left). 

Mesially from the superior frontal sulci we find on each side 
of the brain, but particularly on the left, small segments of Cun- 
ningham's mesial sulcus. 



1 6 AN ESKIMO BRAIN 

The medial frontal sulci of Eberstaller are only fairly well 
represented. 

The ififerior fro?ital sulcus cdiVi be isolated with more facility 
on the left than on the right hemisphere ; it does not connect on 
either side with the inferior precentral sulcus. 

The left inferior frontal sulcus is in two portions ; it begins 
posteriorly 3 mm. in front of the middle of the inferior precentral, 
intersects the anomalous vertical furrow, and terminates about 
2 cm. in front of this furrow in a shallow Y. A few millimeters 
inferiorly and posteriorly to the lower terminal branch of this Y 
begins the second portion of the sulcus. This portion consists 
mainly of the sulcus radiatus, and sends six branches into the 
adjacent convolutions. 

On the right side, that part of the vertical furrow which cor- 
responds to the diagonal sulcus connects, 1.9 cm. above the 
Sylvian, with a short but deep T branch, i.o cm. long, which runs 
directly forward and probably represents the posterior extremity 
of the inferior frontal sulcus. The anterior portion of the same 
consists of the sulcus radiatus, possibly joined with the fronto- 
marginal sulcus. This portion, as on the left, shows six 
branches. One of these connects inferiorly with the anterior 
branch of the presylvian ; another ascends to within a short dis- 
tance of the median frontal sulcus. 

A small independent depression indents on each side the sur- 
face of the pars triangularis of the inferior frontal gyrus. 

All the frontal sulci show numerous submerged annectent 
gyri. 

The anomalous vertical furroiv which runs on each side an- 
terior to and nearly parallel with the precentral sulci, has been 
referred to in the description of the Sylvian. 

The precentral sulcus consists on each side of two independent, 
radiating segments of considerable depth. On the left these 
segments are isolated ; on the right the superior connects, over a 
deep annectent bundle, with the first frontal sulcus, while the 



AN ESKIMO BRAIN 17 

inferior joins and probably forms the superior part of the 
anomalous vertical furrow. 

Above the superior precentral there is on each side an inde- 
pendent, triradiate sulcus extending to the upper border of the 
hemisphere and bounding laterally the ascending frontal con- 
volution ; it looks like a third part of the precentral. 

Orbital Surface. — The Sulcus O If actor ius presents a typical 
conformation. It is a long depression, running from i.o cm. 
at base to 0.5 cm. at terminus laterally to the median fissure, 
quite deep, terminating on the left side in a free line and 
on the right side in a small Y. Slightly anteriorly to the end a 
small transverse sulcus crosses the border of the hemisphere on 
the left, and a small semicircular sulcus indents the border on the 
right side. The parts of the first frontal gyrus traversed by the 
olfactory sulcus are, as previously stated, quite prominent. 

Besides the olfactory, each of the orbital parts shows two 
other antero-posterior sulci. One of these, the outer, is apparently 
the orbital sulcus. Its form on the left is that of a Y, or of a K 
with the lower branch interrupted, while on the right side it 
forms a somewhat crooked X. 

Both of these figures are situated somewhat more externally 
than is usual, and between them and the olfactory furrows we 
find on each side a distinct separate sulcus. On the left this 
sulcus consists of two branches and indents the first frontal con- 
volution. The anterior branch communicates with the main 
ramus of the orbital sulcus. On the right side the sulcus begins 
near the root of the olfactory nerve and then passes forward, 
bounding the first frontal gyrus. 

The transverse orbital sulci present nothing extraordinary. 

Parietal Lobe. — The postcentral sulcus shows neither on the 
left nor on the right any superficial interruption.' It connects on 

' According to Cunningham, in the brains of adult Irishmen the postcentral 
sulcus was found complete and separated from the interparietal sulcus (as on the right 
in the Eskimo brain) in \i%\ it was found complete and communicating with the 
interparietal (as on the left in the Eskimo brain) in 60 % of the hemispheres. 



15 AN ESKIMO BRAIN 

both sides with the Sylvian and on the left side also with the 
interparietal sulcus. 

The left postcentral is very long, reaching to within 0.5 cm. 
of the superior border of the hemisphere, where it connects, over 
an imperfectly submerged gyrus, with a vertical sulcus from the 
precuneus. 

The connection of the postcentrals with the Sylvian is not 
effected by the trans-postcentral sulci. 

The course of both postcentral sulci, and particularly of that 
on the left, is tortuous. 

Each sulcus gives off during its course several incisures and 
small branches. On the left side, 1.4 cm. above the Sylvian bor- 
der, a quite deep branch passes backward through the supra- 
marginal convolution and communicates with , the superior 
terminal branch of the Sylvian. Three cm. above the Sylvian 
the left postcentral connects, over a submerged gyrus, with the 
interparietal sulcus. Opposite this junction a branch, 1.4 cm. long 
and looking like the anterior terminus of the interparietal, passes 
forward and slightly upward into the ascending parietal gyrus. 

In its upper third the left retrocentral sulcus gives off three 
smaller branches. The lowest one of these passes backward ; the 
middle one indents the ascending parietal gyrus and ends near 
the central sulcus ; the third branch passes upward, ending in 
front of the dorsal termination of the paracentral fissure. The 
main limb of the sulcus then bends backward and runs toward 
the aforementioned connection with the precuneal. 

The right postcentral sends off four branches or incisures, 
one of which, 2.0 cm. long, passes backward from near the mid- 
dle of the sulcus. Two and a half cm. above the Sylvian the 
right postcentral connects, over a submerged but not deep 
fascicle, with the central fissure. 

Superiorly the sulcus divides into two branches, the anterior 
1.4 cm., the posterior 2.4 cm. in length, which surround, in the 
form of a broad Y, the extremity of the paracentral sulcus. 




Lateral aspect 



<^ S, j*'«. 








Mesial aspect 
THC HEMISPHERES OF KISHU'S CEREBRUM 



AN ESKIMO BRAIN 1 9 

Each postcentral shows in its course a number of more or less 
deep annectent fascicles. 

The trans-postcentrals are in their usual position, but only 
that on the left (as was the case with the trans-precentrals) reaches 
the dorsal surface of the hemisphere. 

The interparietal sulcus on the left commences, with a small T, 
somewhat inferiorly and anteriorly to the end of the superior 
terminal Sylvian, 1.8 cm. from the Sylvian bifurcation. Seven 
millimeters above its beginning the sulcus connects, over a sub- 
merged but not deep gyrus, with the postcentral. From this, 
point the interparietal runs in a slight curve 4.2 cm. upward and 
backward and joins freely the paroccipital sulcus. The inter- 
parietal gives off three larger branches, one of which runs down- 
ward, into the supramarginal, and the other two upward, into the 
superior parietal gyrus. There are within the sulcus several deep 
but no interrupting connecting bundles. 

On the right side we find an anomalous deep furrow, uninter- 
rupted except by very deep bundles, running from a point well 
down between the supramarginal and angular gyri, in a wavy 
course, parallel in the main with that of the postcentral sulcus 
and central fissure, to and i.o cm. over the superior border of the 
hemisphere, ending on the precuneus. 

From this furrow, above its middle, begins, over a depressed 
but still partly visible gyrus, the horizontal part of the inter- 
parietal. This is angular, but 0.8 cm. long (in a straight line), and 
connects with the paroccipital. 

The vertical furrow separates a stout and prominent con- 
volution which runs parallel with the ascending frontal and 
ascending parietal gyri. The superior portion of the vertical 
furrow lies, independent of both, between the postcentral and the 
anterior curve of the paroccipital sulcus. 

The minor parietal sulci will be mentioned with the descrip- 
tion of the convolutions. 

Occipital Lobe. — The anterior as well as the lateral occipital 



20 AN ESKIMO BRAIN 

sulcus is fairly well represented on both sides. The anterior 
sulcus on the left connects with the ascending branch of the 
superior temporal, the anterior and lateral furrows on the right 
with the anomalous medio-tei7tporal sulcus (q. v.). The lateral 
sulcus on the left is in the form of an H and is without 
connections. 

Temporal Lobe. — The sulci on the superior or intrasylvian sur- 
face of the lobe have been mentioned. 

The lateral surface is higher on the right than on the left side. 
Its sulci are on both sides deep and the gyrations distinct. 

The superior or first temporal sulcus begins on both sides 
in a line near the pole of the temporal lobe. It is preceded on 
the left by a small transverse furrow, on the right by a shallow 
depression. 

The horizontal portion of the superior temporal is continuous on 
both sides. Its form is wavy on the left, more straight on the right 
side. It terminates on the left in a line 1.8 cm. posteriorly to the 
Sylvian bifurcation and within 0.3 cm. of the inferior terminal 
Sylvian. The ascending portion is separate. On the right the 
horizontal portion runs to a point about 1.2 cm. posterior to the 
Sylvian bifurcation, connects with the inferior terminal Sylvian, 
and proceeds without interruption backward and upward as the 
ascending ramus. 

The horizontal portion on the left connects, 1.6 cm. before its 
posterior end, over a submerged but not deep gyrus, with a 
parallel, m,edio-temporaP sulcus, 4.4 cm. long, which separates the 
posterior half of the middle temporal gyrus into an inferior and 
a superior portion. The horizontal branch on the right connects, 
by means of a shallow transverse sulcus, with the second tem- 
poral, and more posteriorly as well as quite superficially with the 
medio-temporal. 

The ascending branch on the left begins with a short vertical 



' This term suggests itself from some similarity of this to the medio-frontal sulcus 
of Eberstaller. 



AJV £ SAT/MO BRAIN 21 

part that connects with the inferior terminal Sylvian. It runs 
backward and slightly upward, almost in line with the horizontal 
portion. It connects with the ascending part of the second tem- 
poral, and finally joins the anterior occipital sulcus. 

On the right the ascending branch runs in an angular manner 
upward and backward, terminating a short distance below the 
paroccipital. This branch also has a shallow connection with the 
medio-teinporal. 

The medio-teinporal sulcus is even better marked on the right 
than on the left. Beginning somewhat posteriorly to a vertical 
from the Sylvian bifurcation, it runs backward and upward, 
parallel with the ascending portion of the first temporal, to the 
occipital lobe. It connects with both the horizontal and ascend- 
ing portions of the first temporal and also with the anterior as 
well as with the lateral occipital sulci. 

Both the first and the rnedio-temporal sulci send off shorter 
branches and all show deep connections passing between the 
adjacent gyri. 

The mean depth of the horizontal ramus of the left superior 
temporal sulcus is 1.8 cm., that of the right, 2.1 cm. The ascend- 
ing rami are not so deep. The depth of the me dio-temp orals is 
less than that of the horizontal, but slightly greater than that of 
the ascending portion of the first temporal sulci. 

The second or middle temporal sulcus is composed on each side 
of two separate segments ; each of these shows some secondary 
ramifications. 

The anterior portion on the left commences with a curve, 
passes in a wider curve backward and slightly upward, and ter- 
minates, nearly vertically below the central fissure, with several 
marked radiations. The posterior left segment begins in a Y 
slightly above and posteriorly to the termination of the first part, 
and runs slightly downward and backward, to and along the in- 
ferior border of the hemisphere, terminating in a simple manner 
about 1.6 cm., in a straight line, from the occipital pole, under the 



22 AN ESKIMO BRAIN 

lateral occipital sulcus. Two and seven-tenths of a cm. anteriorly 
to its end this segment gives off, over a deep annectent fascicle, 
an ascending portion, which runs with several bends directly up- 
ward to connect with the ascending part of the first temporal 
sulcus. 

On the right side, the first portion of the second temporal has 
its simple beginning i.o cm. in a straight line from the pole of 
the temporal lobe ; it passes 4.6 cm. backward and ends in a 
small bifurcation. A short distance anteriorly to this bifurcation 
the sulcus communicates with the first temporal. 

The posterior segment on the right begins a little posteriorly 
to the bifurcation of the first part, in the form of a doubly curved, 
nearly transverse line. This line bends, runs backward and down- 
ward, reaches the inferior border, sends a 1.3 cm. long branch 
backward and inward into the third temporal gyrus, passes again 
to the dorsal surface of the hemisphere, and ends in a long Y 
figure, the lower extremity of which reaches to below the lateral 
occipital sulcus. 

The third or basitemporal sulcus is unusually well developed, 
particularly on the left side. 

The sulcus on the left is continuous, somewhat wavy in form, 
and measures 9.3 cm. in length (in a straight line). It effects 
a shallow connection with the collateral. 

The right sulcus consists of three large separate segments, 
which extend from near the pole of the temporal lobe to within 
1.7 cm. of the occipital pole. The segments send off a number 
of radiating branches, and the posterior one connects with the 
collateral. 

On both sides the third temporal sulcus contains a number of 
submerged, more or less deep, annectent fascicles. 

THE INSULA 

The conformation of the surface of the island is quite similar 
on the two sides of the brain (figs. 57, 58). 



AN ESKIMO BRAIN 



23 



The marginal or limiting sulci of the insula are very deep, 
especially anteriorly, and they are continuous, except over the 
antero- inferior ex- 
tremity or pole of 
the insula. 

The superior 
limiting sulcus com- 
municates on both 
sides with the two 
branches of the pre- 
sylvian; it also gives 
off on each side two 




Fig. 17 — Left Insula. S.L.S., S.L.A., S.L.P., Sulci limitantes 
insulae, superior, anterior, posterior; S.C.I., Sulcus centralis 
insulae ; S.P-c. I., Sulcus post-centralis insulae. 




Fig 



Right insula. P-s.A., Presylvian anterior; P-s.P., Pre- 
sylvian posterior ; S.D., Sulcus diagonalis ; a, Trans-precen- 
tral sulcus ; F.C., Central fissure ; b,Trans-postcentral sulcus ; 
c, Postcentral sulcus. 



short branches up- 
ward, and a deep 
short incisure down- 
ward, into the insula 
itself. The average 
depth of the su- 
perior limiting sulci 
is 2.8 cm., and in the 
course of each there 
are several strong 
annectent fascicles 
passing between the lobes of the island and the overlying 
opercula. 

At the posterior inferior angle of the insula there are two strong, 
almost superficial annectent bundles, connecting the superior tem- 
poral gyrus with the insula ; there is on each side also a strong 
connecting bundle between the anterior extremity of the posterior 
lobe of the insula and the superior temporal convolution. 

The central sulcus of the insula is independent on the left, 
but it communicates with the superior limiting sulcus on the 
right side. The central sulci average only 0.5 cm. in depth, and 
each shows anteriorly a submerged anastomotic fascicle. 



24 AN ESKIMO BRAIN 

Besides the above sulci, each insula shows a small furrow 
which divides its posterior lobe into superior and inferior por- 
tions (sulci retrocentrales insulse). There is also on each side 
a curving but not very deep sulcus which passes from below over 
the pole of the insula. This sulcus ends freely on the anterior 
lobule of the insula on the right, but joins the anterior limiting 
sulcus on the left side. 

The anterior and posterior lobes of the insula are well defined 
and show the ordinary planes. Gyri breves fairly well marked. 

CONVOLUTIONS 

Frontal Lobe. Dorsal Surface. — The frontal gyri are rather 
more complex and tortuous than in average whites. The dorsal 
portion of the left superior frontal gyriis is slightly narrower in 
front than that of the right (left 2.85 cm., right 3.05 cm.), but 
somewhat broader posteriorly (left 2.8 cm., right 2.5 cm.). In 
about the middle, the left gyrus sends downward a prominent, 
shoe-like convolution, which indents the middle frontal gyrus. 
The dorsal parts of both superior frontal convolutions show, be- 
sides the segments of the sulcus mesialis of Cunningham, a con- 
siderable number of transverse depressions. 

The middle or second frontal gyrus is on both sides of an 
irregular form and partly subdivided by the medial frontal sul- 
cus. The posterior portion of the convolution on the left is es- 
pecially well developed, and is separated from the more anterior 
portion by the vertical furrow. Both middle frontal gyri have 
numerous superficial and deep connections with the neighboring 
convolutions. 

The inferior or third frontal gyrus is in this brain, contrary 
to the general rule, more extended antero-posteriorly and more 
redundant on the right than on the left side. This excess is 
especially marked in the right middle or triangular part (cap of 
Broca). 

The convolution shows numerous connections ; the orbital and 



AN ESKIMO BRAIN 2$ 

triangular parts connect on both sides superficially with the middle 
frontal gyrus. 

The ascej^dmg- fro7tta/ convolution is somewhat stronger on the 
right than on the left. It is on both sides most slender in its 
middle fourth. It is on both sides continuous from the Sylvian 
fissure to the superior border of the hemisphere. Superficial con- 
nections. — On the left : a broad isthmus to the inferior frontal ; 
a superficial annectent gyrus to the middle frontal ; similar gyrus 
to superior frontal ; and, at the median border of the hemisphere, 
three superficial annectent gyri, one to the superior frontal, one 
to the paracentral, and one to the ascending parietal convolu- 
tions. On the right there is a broad superficial connection with 
the pars basilaris of the inferior frontal ; and similar connections 
anteriorly with the middle and superior frontal, and superiorly 
with the paracentral and ascending parietal gyri. 

Mesial Surface. — The left marginal gyrus is considerably 
higher than the right one. Its height is, from the orbital surface 
to the calloso-marginal fissure, on the left 2.2 cm., on the right 
1.8 cm.; opposite the anterior pole, on the left 3.2 cm., on the 
right 2.5 cm. ; and the average height of the upper part is, on the 
left 2.6 cm., on the right 2.3 cm. On both sides the marginal and 
the calloso-marginal gyri stand to each other, as to size, in an in- 
verse relation. 

The inferior extremity of each marginal gyrus is marked by 
the sulcus rostralis transversus and connects almost superficially 
with the inferior extremity of the limbic lobe (carrefour olfactif 
of Broca). The posterior extremity of the marginal gyrus com- 
municates on the left by two superficial, on the right by one 
superficial and one deep, annectent gyri with the paracentral 
lobule. 

As to the convolutions on the orbital surface of the frontal 
lobes, on the left the first and third frontal gyri, both markedly 
developed, join a little posterior to the middle of the surface, and 



26 AJV ESKIMO BRAIN 

the second frontal gyrus forms a wedge anteriorly between them. 
On the right, the second passes between the first and third gyri 
as a narrow band to the root of the olfactory nerve, where it joins 
the extremities of the other frontal convolutions. 

The olfactory tracts and bulbs show nothing unusual. 

The Parietal Lobe. — The asceitding parietal gyrus is somewhat 
more voluminous on the left hemisphere (average width on the 
left about 1.2 cm., on the right about i.o cm.). The base of the 
convolution on the left measures, antero-posteriorly, 3.2 cm., of 
that on the right 1.9 cm. Both gyri show a constriction between 
their lower and middle thirds, and a marked development of the 
latter portion. The upper third is on each side slender, tapering, 
and not raised fully to the niveau of the neighboring parts. 

The upper extremity of the gyrus connects superficially with 
the ascending frontal, paracentral, and superior parietal convolu- 
tions ; the lower part connects, by means of submerged but not 
deep fascicles, with the ascending frontal and supramarginal gyri. 

The superior parietal gyrus is throughout somewhat larger on 
the left side. Anteriorly it communicates on both sides super- 
ficially with the ascending parietal, and in a similar way posteriorly 
with the superior occipital convolution. Inferiorly there are nu- 
merous submerged fascicles of connection between the superior 
and inferior parietal gyri. 

The left superior parietal convolution is separated by trans- 
verse sulci into two parts, the middle of which is very redundant. 
The right gyrus is somewhat similarly divided into two portions, 
of which the anterior is the more redundant. 

The convolution shows on each side a number of lateral and 
surface indentures. 

Th.Q paroccipital gyrus forms on each side a well-marked loop, 
which surrounds the extremity of the parieto-occipital fissure. 
The left gyrus is larger than the right one. 

The inferior parietal convolution as a whole is larger on the 



AN ESKIMO BRAIN 2/ 

right, compensating for tlie smaller size, on that side, of the supe- 
rior parietal. 

The supramarginal gyriLs is fairly well defined on the left and is 
divided from the angular gyrus by a vertical branch proceeding 
from the interparietal sulcus (the sulcus intermedins primus, Jen- 
sen, Eberstaller). On the right side the marginal convolution is 
larger and more redundant ; its operculum, or the triangular 
part between the two terminal branches of the Sylvian fissure, is 
especially well developed. The gyrus is bounded posteriorly by 
the inferior extremity of the vertical parietal sulcus. 

The angidar and postparietal gyri are nicely differentiated 
loops, separated by a vertical depression (sulcus intermedius 
secundus, Eberstaller) on the left, but are of irregular form and 
separated only from below by the extremity of the ascending 
branch of the superior temporal sulcus on the right side. 

All the parts of the inferior parietal convolutions show minor 
lateral or surface indentations, and numerous deep as well as 
superficial connections. 

The paracentral lobule is much better isolated anteriorly on 
the left than on the right. The left lobule is also slightly more 
redundant, though slightly less high and not any longer than that 
on the right side. 

The surface of the left lobule is indented by two Y-shaped and 
one lineal, that of the right by one Y-shaped and two lineal, sulci. 

Precuneus. — This lobule is separated completely on the left, 
incompletely on the right, from the limbic gyrus, by the posterior 
limbic or subprecuneal sulcus. The surface of the left precuneus 
is indented by four vertical sulci, two of which connect with the 
posterior limbic, while the other two pass over the border of the 
hemisphere, where the anterior communicates with the posterior 
terminal branch of the postcentral sulcus, and the posterior one 
forms the anterior boundary of the paroccipital gyrus. On the 
right, the precuneus presents a Y-shaped sulcus in connection 



28 AN ESKIMO BRAIN 

with the intraHmbic and postlimbic sulci, while its superior 
portion is indented by the terminus of the anomalous vertical 
parietal sulcus. 

Both the paracentral lobule and the precuneus show numerous 
deep, besides the superficial, connections with the adjacent gyri. 

Occipital Lobe, — The lobe measures, from the antero-inferior 
extremity of the cuneus to the occipital pole, on the left 4.7 cm., 
on the right 4.9 cm., which is respectively 26.1 % and 27.4^ of 
the whole length of the hemisphere (see also additional measures). 

The gyration of the lobe in the Eskimo brain under con- 
sideration is not inferior to that met ordinarily in whites. It 
presents, as is often the case, some difficulty to analysis, but no 
very extraordinary features. 

The cuneus is bounded by almost straight lines. It is lower, 
but longer, on the right hemisphere. Its superior border is in- 
dented on the left by two, on the right by one incisure. Its sur- 
face shows on the left an independent triradiate sulcus with 
branching extremities ; on the right a large, somewhat Y-shaped 
sagittal sulcus, which connects with the parieto-occipital, and a 
quadriradiate sulcus, one of whose branches connects with the 
collateral. 

Temporal Lobe. — Tho: superior temporal gyrus is considerably 
stronger on the right than on the left side (mean height of the 
left, 0.8 cm. ; of the right, i.i cm.). The left gyrus is particularly 
slender and is slightly depressed in its middle. 

The left convolution is interrupted by one of the transtem- 
poral furrows which connects with the superior temporal sulcus. 

The right superior temporal gyrus appears to be composed 
of three imperfectly separated portions, namely, a long anterior 
part, reaching to within i.o cm. of the bifurcation of the Sylvian, 
separated from the rest of the gyrus by two incisures (one 
superior and one inferior), which almost meet, and a shallow de- 
pression. The more anterior of the following two parts is in the 



AN ESKIMO BRAIN 2g 

form of a larger oblong lobule, situated between the depression 
just mentioned and the connection of the inferior terminal Sylvian 
with the superior temporal sulcus. The third part is a small, 
partly depressed isle projecting from the second part into the 
Sylvian and separated from that part by a shallow sulcus. 

The middle or second temporal gyrus is also more voluminous 
on the right side ; both are quite redundant. 

The anterior half of the convolution on the left is curved, on 
the right straight and wedge-shaped. The posterior half on each 
side, somewhat less redundant, is divided into two parallel, 
nearly equally strong portions by the secondary medio -temp or at 
sulcus. 

The anterior portion of the right gyrus is indented by two 
vertical sulci proceeding from the second temporal ; the anterior 
of these connects with, while the posterior reaches very near to, 
the first temporal sulcus. 

The superior posterior portion of the right gyrus is separated 
by a connecting branch between the first and medio-temporal 
sulci. 

Both gyri show a number of more or less marked lateral in- 
cisures and a few minor surface furrows. 

The inferior or third temporal gyrus lies, on both sides of this 
Eskimo brain, almost wholly on the inferior surface of the tem- 
poral lobe. It is easily isolated. 

The gyrus is on both sides strongest in about its middle third, 
its anterior and posterior extremities tapering a little. It is on 
each side incised by a number of incisures which pass into it 
from both the second and third temporal sulci, but it is nowhere 
totally interrupted. In its middle enlargement the gj^rus is on 
each side indented by an independent ramifying sulcus, which 
on the left has the form of a double joined Y, and on the right 
approaches the form of H. Excepting the anterior and pos- 
terior, the gyrus has one superficial connection on the left 
(with the anterior portion of the second temporal) and two on 



30 AN ESKIMO BRAIN 

the right side (with the anterior part of the second temporal and 
with the fusiform lobule). 

T\v^ fusiform gyms ^ well defined on both sides, is throughout 
more voluminous on the right. The left gyrus shows, near its 
posterior third, a shallow interruption. The borders of both 
convolutions are indented by a number of more or less pro- 
nounced incisures. The gyri show numerous submerged con- 
nections with the third temporal and the lingual convolutions. 

The lingual gyrus, well defined, connects on both sides, 
anteriorly, superficially, and freely, with the gyrus hippocampi ; 
posteriorly, near the occipital pole, with the fusiform lobules. 

The gyrus is partly divided on both sides into halves by a 
branch from the collateral fissure. The anterior portions are some- 
what tongue- or pear-shaped, the tapering ends connecting with 
the hippocampal gyri, and each is indented by a quite prominent 
sagittal sulcus. The posterior extremity of this sulcus, on the 
right, connects with a branch from the collateral. The posterior 
half on the left is nearly straight and more slender than the an- 
terior one ; that on the right forms a marked loop. The surface 
of the posterior portions, also, is indented on each side by a small, 
mainly sagittal depression. 

THE LIMBIC LOBE 

This lobe differs remarkably on the two sides. It is much 
larger over almost its entire extent on the right side, as will be 
indicated by the following measures (taken between the sulcus of 
the callosum and the external boundary of the gyrus) : 

Left Right 

Antero-inferiorly, below the rostrum (above Broca's 

carrefour olfactif) 0.3 cm. 0.5 cm. 

Anteriorly (horizontally) 0.5 cm. i.o cm. 

Superiorly, beneath the first frontal or marginal 

gyrus 0.85 cm. 1.5 cm. 

Superiorly, below the paracentral lobule 1.5 cm. 2.1 cm. 

Superiorly, below the precuneus 2.0 cm. 2.6 cm. 

Posteriorly, opposite the cuneus t.6 cm. 1.4 cm. 



AN ESKIMO BRAIN 3 1 

The lobe begins on both sides at the well-developed olfactory- 
lobule or space of Broca, below the rostrum of the callosum. Its 
ascending portion and a part of its horizontal portion are entirely 
smooth on the left ; on the right side the external boundary of these 
parts shows many depressions, and the horizontal part is traversed 
by the previously described sagittally running, shallow sulcus. 

All the parts of the limbic lobe behind the line which bounds 
anteriorly the paracentral lobule are much more developed than 
the parts anterior to this line. On the left this posterior portion 
of the lobe is traversed by a number of transverse sulci and has 
the appearance of being composed of four or five loops lying in 
close apposition. On the right, there is a somewhat similar for- 
mation of loops, but their outHne is more angular. Directly 
beneath the splenium both lobes become very narrow and soon 
after blend with the hippocampal convolutions. 

Deep bundles connect the limbic lobe on each side with the 
mesial part of the first frontal gyrus and the parietal lobule. 
The connections of the lobe with the precuneus are on the left 
all submerged, though not deep, while on the right side besides 
these deep bundles there is also, posteriorly, a superficial annectent 
gyrus between the two structures. A few deep fascicles pass 
between the lobe and the cuneus and lingual gyrus. 

HIPPOCAMPAL GYRUS 

This gyrus is somewhat larger on the right side. It is almost 
isolated externally on the right, only a small annectent gyrus 
passing from it, between the fissura rhinica and the inferior 
temporal sulcus, to join the fusiform convolution. On the left 
side this connection is broader. The surface of the gyri is 
smooth. Both gyri connect superficially with the lingual con- 
volutions. The uncus is well marked on both sides. 

The parts within the limbic lobe show nothing extraordinary. 
The callosum is exceptionally strong and very nearly equal on 
the two sides. Its measurements are as follows : 



32 AN ESKIMO BRAIN 

Diameter antero-posterior maximum 7.9 cm. 

Maximum height of anterior enlargement 1.45 cm. 

Maximum height of posterior enlargement 1.5 cm. 

Maximum height between the enlargements i.o cm. 

Minimum height between the enlargements 0.75 cm. 

The dentate gyrus is well differentiated and the fimbria well 
developed. 

Cerebellum, Pons, Medulla 

All these parts appear to be very well developed ; they are 
symmetrical and present no gross deviation from the shape 
and conformation of the same parts as generally observed in 
whites. 

Measurements of Cerebellum 

Height maximum 5.7 cm. 

(in fresh brain 5.8 cm.) 

Diameter antero-posterior maximum ^ 6.8 cm. 

(in fresh brain 7.0 cm.) 

Width maximum "^ 10.4 cm. 

(in fresh brain 10.6 cm.) 

Antero-posterior length of worm 4.3 cm. 

Maximum height of worm 4.0 cm. 

Maximum depth of anterior fossa 2.2 cm. 

Maximum depth of posterior incisure 1.3 cm. 

Depth to the top of the worm (from a plane corresponding to 

the highest points on each cerebellar hemisphere). 1.3 cm. 

Measurements of the Pons 

Width maximum 3.5 cm. 

Height (vertical) from fourth ventricle 2.9 cm. 

Length (antero-posterior) 2.5 cm. 

Measurements of the Medulla 

Thickness maximum infero-superiorly 1.8 cm. 

Thickness maximum laterally 2.0 cm. 

' About 1.0 cm. from the median line on each side. 

' At about the junction of anterior third with posterior two thirds. 



AN ESKIMO BRAIN 



THE CEREBELLUM 



33 



The great horizontal fissure encircles the organ completely. 
It averages 1.6 cm. in depth. On its bottom many slender rods 
are seen to pass from one part of the cerebellum (superior) to 
the other (inferior), all directed obliquely outward. (There are 
similar rods within all the other sulci.) 

All the usual lobes of the upper surface (as well as all the 
divisions of the worm) are present and well developed. There 
are two lobules situated laterally to the lingula (which faces for- 
ward) ; these two lobules are joined 2 cm. outward to the alae 
lobuli centralis. These last are very small and hidden. The 
lingula, with the wings and the central lobule, gives a very good 
appearance of a moth, with wings converging upward. 

Central lobe small. Folium cacuminis double ; uvula con- 
sists of eight segments of which the last two (in pyramid) are 
small. 

The pyramid is breast-shaped, with the apex posteriorly and 
a deep notch anteriorly ; into this notch are received the last two 
little segments of the uvula. The lateral masses are anteriorly 
separated and form two distinct parts, applied over the ex- 
tremity of the uvula. The parts connect anteriorly by deep 
annectent fascicles with the cerebellum. Tuber portions small. 
None of the lobes and parts of the lower surface and lower worm 
present anything extraordinary. 

Summary of the Main Peculiarities of Kishu's Brain 

As a whole, this Eskimo brain is heavier and larger than the 
average brain of white men of similar stature. The excess of 
weight over the averages of both Broca's and Manouvrier's speci- 
mens (averages which agree well with those obtained by Bischoff, 
Boyd, Sims, Huschke, and other observers) amounts to almost 
150 grammes. 

As to size, the average antero-posterior diameter of the white 
male brain ranges, according to Huschke, between 16.0 and 17.0 



34 A AT ESKIMO BRAIN 

cm. (mean 16.5 cm.), and the average maximumlateral diameter 
14.0 cm. The mean of these measures, which largely removes 
the disturbing element of the shape of the brain, is 15.25. The 
crude measurements of Kishu's brain amount, for the length, to 
18.0 cm. for the left and 17.9 cm. for the right hemisphere, and 
13.6 cm. for the maximum breadth of the cerebrum. These 
figures give us the mean of 16.5, which is to that in whites as 
108.2 to 100. 

The different parts of the brain do not show the same relative 
weight proportions as they do in the average white brain, and 
the same is true of the relative size of the principal parts of the 
cerebrum. The cerebellum, and particularly the pons with the 
bulb, is relatively somewhat heavier in Kishu than in whites ; 
while as to the main cerebral parts the most remarkable feature 
is the relative smallness of the parietal portion (see additional 
measurements). 

In its external conformation this Eskimo cerebrum rather ex- 
ceeds that of an average white male in the number, extent, and 
depth of the sulci, and in the complexity of the gyrations. 

Both hemispheres, and especially the right one, show a gen- 
erally marked tendency to vertical gyration. The left side shows 
one, the right two, large, anomalous, composite, vertical furrows. 
The gyration of the left hemisphere is in general somewhat more 
complex than that of the right one. 

The pars triangularis of the inferior frontal convolution, the 
temporal lobe, inferior parietal gyrus, and limbic lobe are all 
larger on the right than on the left ; on the other hand, the 
mesial part of the superior frontal gyrus, the middle frontal gyrus, 
the paracentral lobule, the precuneus, and the mass of the occipi- 
tal lobe, are larger on the left than on the right side. 

There is a great length of the postcentral sulci, particularly of 
that on the left. The left Sylvian (main limb) is longer, the left 
central fissure is situated (in a horizontal direction) slightly more 
posteriorly and is slightly more vertical than the right. There is 



AN ESKIMO BRAIN 35 

a bilateral, longitudinal division of the mesial part of the supe- 
rior frontal gyrus and a tendency on the right to a similar division 
of the limbic lobe ; and on each side there is a pronounced medio- 
temporal sulcus, dividing sagittally the posterior part of the mid- 
dle temporal convolution. 

Besides those enumerated, there are many other interesting 
minor features of the brain which need not be repeated. 

Comparative Notes 

The collection in the Medical Department of Columbia Uni- 
versity includes, besides that of Kishu, the brains of three other 
Eskimo of the same party and originally from the same locality 
(Smith sound). One of these specimens is from Nooktah, a man 
older than Kishu ; another from Atana, a woman of about the 
same or a little more advanced age than Kishu ; and the third 
from Avia, a girl of ten to twelve years of age. A detailed report 
on these three brains is being prepared, as hitherto mentioned, 
by Mr E. A. Spitzka ; my independent work on the same extends 
over those points only which are of particular interest in connec- 
tion with the specimen here described, including the more im- 
portant measurements. 

The general gyration in these additional Eskimo brains, com- 
pared with that in average adult whites, is very good, particu- 
larly over the frontal lobes, in Nooktah, good in Atana, rather 
simple in Avia. In all the external conformation is more com- 
plex on the left hemisphere. The frontal gyration in Nooktah is 
not less complex than that in Kishu, but the whole brain of the 
latter is more developed and richer. 

The insulae are both quite exposed anteriorly in Atana, 
less so in Avia, and covered, or very nearly so, in Nooktah as 
well as in Kishu. 

The ascending frontal gyri are both very strong in Atana, the 
ascending parietal gyri on both sides and the ascending frontal on 
the right in Avia. 



36 AN ESKIMO BRAIN 

The anterior and posterior portions of the presylvian are sepa- 
rate in all three brains, as in that of Kishu. 

The central fissure, which in Kishu commenced in the Syl- 
vian, has a similar origin on the right side in Avia ; in all other 
instances it reaches near to the Sylvian. The superior termina- 
tion of the fissure reaches the superior border in Nooktah and on 
the right in Atana, and passes slightly to moderately over it on 
the left in Atana and on both sides in Avia. In the girl the 
course of the fissure is remarkably vertical. 

A longitudinal division of the mesial part of the superior 
frontal gyrus, found in Kishu, is also present complete on left, 
interrupted on right, in Nooktah ; slightly incomplete on left, 
small traces on right, in Atana ; and on the right in Avia. 

The limbic lobe shows traces of longitudinal division, as on 
the right in Kishu, on the right in Nooktah, and on the left in 
Avia. The lobe that shows the traces of division is in both 
cases, so far as these traces extend, higher than that of the op- 
posite side, as was* also the case in Kishu. 

A furrow somewhat similar to the pre-precentral vertical 
furrow in Kishu is seen on the right in Nooktah, while sinu- 
osities, somewhat similar to the right vertical post-postcentral 
one in Kishu, occur on the left in Atana and on the right in 
Avia. 

The postcentral sulcus is single in all cases, except on the 
left in Avia, where it exists in two portions. 

The temporal lobe is slightly higher on the left side in Nook- 
tah and Avia (see the measurements). The first temporal gyrus 
is in all cases moderately to well developed. The medio-tem- 
poral sulcus, though present in segments in Nooktah and Atana, 
is by no means as clearly distinguishable as in Kishu. 

Broca's cap, or that part of the inferior frontal convolution sit- 
uated between the two portions of the presylvian, is, contrary to 
what was the case in Kishu, in all these brains better developed 
on the left side. 



AN ESKIMO BRAIN 37 

The extremities of the occipital lobes are in all three brains 
of about equal size and not disproportionate as in Kishu. 

Additional and Comparative Measurements 

The subject of brain measurements is still in its infancy. 
Although many brains have been measured, particularly since 
Huschke and Broca, there is yet no standard system of encepha- 
lometry comparable with that of the measuring of the head 
or cranium. Every author of importance has thus far chosen his 
own points from which to measure, and there is no regulation of 
either the methods or instruments. There is no more important 
part of the body and at the same time no part with which more 
care and accuracy are required in measuring, than the brain, and 
these two conditions ought to prompt an early and thorough 
systematization of procedure. As it is, the brain measurements 
of one author can scarcely be compared or joined with those of 
any other. 

The most disturbing factors in measuring the brain are, first, 
its softness and the consequent yielding and deformation of the 
organ when removed from the cranial cavity ; this difficulty can 
now be effectually counteracted by a formaline-alcohol or forma- 
line hardening of the organ before the opening of the skull. 

The second important factor, which thus far has not received 
sufficient attention, is the different shape of the brain in different 
individuals and especially in different races. No one would think 
of comparing, or uniting in a series, the dimensions of a dolicho- 
cephalic with those of a brachycephalic skull, and similar distinc- 
tions should be established in brain measurements. 

The choice of instruments is very important. Even if the 
tape only be used, considerable differences in the measurements 
are obtained according to the width of the same. 

Some, and perhaps many, of the measurements of the brain 
carry valuable indications which we today do not appreciate. 
The knowledge of the organ will certainly progress, and meas- 



38 AN ESKIMO BRAIN 

urements taken with care, even if not essential now, may in the 
future be found of value. 

A more detailed discussion here of these important matters 
would be somewhat irrelevant to the subject of this paper. The 
above remarks are thought to be a proper introduction to the 
following figures and comparisons. 

The measurements of Kishu's brain, which was carefully pre- 
served, between cotton, in a mixture of formaline and alcohol, 
are, as I have certified on the skull, almost absolutely correct. 
The brains of Nooktah, Atana, and Avia were preserved in a 
weak solution of formaline. Nooktah's brain is fairly well pre- 
served and its measurements are apparently quite correct ; the 
brains of Atana and Avia, however, have suffered a rather con- 
siderable change in form, and the absolute measurements of these 
specimens have but little meaning. The relative proportions of 
the various parts of the cerebrum were undoubtedly much less 
affected than the absolute measurements and are probably still fit 
for consideration. 

The surface measurements were taken by a tape 0.8 cm. 
broad, while the diameters were obtained on a graduated plane 
(Mathieu's) and by the accurate sliding compass used in osteom- 
etry. Three repeated measurings gave fairly even, though in but 
very few instances exactly the same, results. 

The points from which the various dimensions were taken and 
the methods will be explained with each measurement. 

Measurements 
approximate length of the lines of norma anterior, kishu : 

Left Right 

Antero-lateral lines 11.5 cm. 10.3 cm. 

Anterior lines ^ 8.3 cm. 

Postero-lateral lines 8.2 cm. 7.8 cm. 

Posterior lines ^ 5.9 cm. 

^ Taken between two cardboards applied to the antero-lateral planes of the brain, 
the line measured touching the anterior surface of the frontal lobes. 
^ Obtained in a way similar to that of the anterior lines. 



AN ESKIMO BRAIN 39 

MAXIMUM LENGTH OF THE HEMISPHERES 

Left Right 

Kishu 18.0 cm. 17.9 cm. 

Nooktah 16.8 cm. 17.0 cm. 

Atana (17.1cm.) (17.1cm.) 

Avia (15.3 cm.) (15.3 cm.) 

In one of the males the length of the left exceeds slightly 
that of the right hemisphere, while in the other male the condition 
is reverse ; in the two females the length of both hemispheres is 
equal. 

In whites the left hemisphere is almost generally slightly 
longer (Eberstaller/ Cunningham ^). 

MAXIMUM WIDTH OF THE CEREBRUM ; CEREBRAL INDEX, COMPARED 

TO CEPHALIC {on the living). 

r Breadth X ioo \ / Breadth of Head X ioo \ 
^ Length ' V Length of Head ^ 

Kishu 13.6 cm. 75.8 76.26 

Nooktah 13.1cm. 77.5 81.4 

Atana (12.3 cm.) (71-9) 80.6 

Avia (11. 6 cm.) (75-8) 72.9 

It can be seen that while the brains of Kishu and Nooktah 
have kept nearly the same relative proportions as they must have 
had in life, that of Atana became relatively longer and narrower 
and that of Avia shorter. 

ARC MEASURES ALONG THE SUPERIOR BORDER ^ 
a. Anterior Point (Cun7iingham) to Central Fissure. 
Left Right 

Kishu.. 17.0 cm. or 63.0^, 17.7 cm. or 65. i^ of the total mesial length. 
Nooktah 16.7 cm. or 66.5 ^, 16.7 cm. or 64.5 ^. 
Atana.. (15.3 cm. or 59.8^), (15.0 cm. or 60.5 ^). 
Avia.. (15.5 cm. or 64.6^), (15.0 cm. or 62.5 ^). 

^ Eberstaller, Das Stirnhirn, Wien and Leipzig, 1890. 

^Cunningham, D. J., " Contrib. to the Surface Anatomy of the Cerebral Hem- 
ispheres." Roy. Irish Acad., Cunningham Mem., vii, 1892. All the following 
references to Cunningham relate to this work. 

^ Eberstaller measured from the anterior perforated space to the occipital pole. 
Cunningham, whom I follow, takes the same measures "from a point on the upper 
or mesial border which corresponds to the level of the outer part of the superciliary 



40 AN ESKIMO BRAIN 

This relative length of the precentral part to the total mesial 
arc, this latter being taken as lOO, is termed by Cunningham the 
frontal or front o-Rolandic index, and is in whites, according to 
the same author (pp. 55, 175), as follows : 

In 12 54" to 6-|- mos. embryos 52.7 

In 24 full-term foetuses 53.5 

In 82 adults 53.3 

In apes and monkeys from 55.9 

in chimpanzee to 45.4 

in mangaby. 

b. Central to Parieto-Occipital Fissure 
Left Right 

Kishu 4.3 cm. or 15.9 ^, 4.3 cm. or 15.8 ^ of the mesial arc. 

Nooktah.. . . 3.9 cm. or 15.5 ^, 5.0 cm. or 19.3 % of the mesial arc. 

Atana (5.8 cm. or 22.7 ^), (5.2 cm. or 21.0 ^) of the mesial arc. 

Avia (5.1 cm. or 21.2 ^), (5.3 cm. or 22.1 <fo) of the mesial arc. 

Cunningham, who terms the proportion of the central parieto- 
occipital fissure segment to the whole mesial arc (this being taken 
as 100, Xh^ parietal index), obtained the following in whites (p. 55): 

Parietal Index 

In 12 5I to 6^ mos. embryos 28.5 

In 24 full-term foetuses 25.7 

In 82 adults 25.5 

In 4 orangs 21.3 

Further, in 4 chimpanzees 19.9 

In 5 cynocephali 22.6 

In 5 macaques 19.0 

In 7 cebi 20.6. 

margin of the frontal lobe. This border is very far from being horizontal. Its outer 
part is on a much higher level than the inner part. As it is traced inwards it is seen to 
take a sudden curve downwards towards the cribriform plate of the ethmoid bone, 
where it merges with the mesial border. A line drawn horizontally inwards from the 
high outer part of the superciliary border of the frontal lobe cuts the mesial border of 
the cerebrum at the point which I arbitrarily selected as the anterior end of the cere- 
brum. It lies, as a rule, just below the most projecting part. Behind I took the mo.st 
prominent part of the occipital pole." " The first of these points maybe distinguished 
as the frontal point ^ and the latter as the occipital point. Further, the distance between 
these two points measured along the upper border of the hemisphere may be termed 
the mesial lengthy (Loc, cit., pp. xi, xii.) 

Cunningham's anterior point has no advantage over that of Eberstaller, and I em- 
ploy it only to enable comparison of my own with Cunningham's indices. 



AN ESKIMO BRAIN 4 1 

c. Parietfl-occipital Fissure to most Pj'ominent Point on ike Occipital Pole 
Left Right 

Kishu 5.7 cm. or 2 1. 1 ^, 5.2 cm. or 19. i ^ of the mesial arc. 

Nooktah. . . .4.5 cm. or 17.9 ^, 4.2 cm. or 16.2 ^ of the mesial arc. 

Atana (4.5 cm. or 17.6 ^), (4,6 cm. or 18.5 ^) of the mesial arc. 

Avia (3.4 cm. or 14.2 ^), (3.7 cm. or 15.4 ^) of the mesial arc. 

Cunningham terms the relative distance of the parieto-occipital 
fissure from the most prominent point in the occipital pole the 
occipital index ^ and obtained for whites (pp. 55, 56): 

In 12 5}-6J mos. embryos 18.8 

In 24 full-term foetuses 20.8 

In 82 adults 21.2 ; also, in 

4 orangs. 23.2 

4 chimpanzees 24.2 

5 cynocephali 29.7 

5 macaques 31.0 

7 cebi 33.0. 

Among adult whites, in 45 men the occipital index was 20.8 ; 
in 35 women the occipital index was 21.7. 
The total mesial arc (from the anterior point, Cunningham, 
to the most prominent point on occipital pole) was : 



Kishu. . . 
Nooktah. 
Atana. . . 
Avia 



Left 


Right 


27.0 


27.2 


25-1 


25-9 


(25.6) 


(248) 


(240) 


(24.0), 



The above indices show in the Eskimo some remarkable features 
which are undoubtedly more than individual variations. There are 
in all the Eskimo, but especially in the men, relatively high frontal 
and low parietal indices. The parietal indices in the two females 
and the occipital indices in the two males and the adult female, 
though also lower, approach more those in whites. There is in 
the four Eskimo, according to these surface measurements, rela- 
tively a more extended superior frontal and a more restricted 
superior parietal area than in the average whites.^ 

^ Compare in this connection, and with the horizontal dimensions that follow, the 
seemingly conflicting measures of Fere, Passet, and Giacomini, referred to by Dejerine, 



42 AN ESKIMO BRAIN 

There is another and somewhat more accurate way in which 
the dimensions of the main parts of the cerebrum may be deter- 
mined. If the hardened hemisphere is placed on the graduated 
board in such a way that the most prominent frontal and occipital 
points are on a line which runs lengthwise along the middle of 
the board, we can then secure, by means of two vertical planes 
and a rod-measure or an ordinary compass, any desirable horizon- 
tal distance from the cerebral extremities. Such distances, com- 
pared with the total horizontal length of the hemisphere, give 
indices which are somewhat more accurate and perhaps not inferior 
in value to those obtainable by surface measuring. Following 
this procedure on the Eskimo brains, I have obtained the following 
figures and proportions: 

a. Horizontal Lengthy Frontal Pole to Superior Extremity of Central Fissure 

Left Right 

Kishu..., 10.9 cm. or 60.6 ^, 10.8 cm. or 60.4 ^ 

of the length of the hemisphere. 
Nooktah.. 10.9 cm. or 64.9 ^, 10,7 cm, or 62.9 ^ 

of the length of the hemisphere. 
Atana (9.6 cm. or 56.1 ^), (10. o cm. or 58.5 ^) 

of the length of the hemisphere. 
Avia (9.8 cm. or 64.1 ^), (9.3 cm. or 60.8 ^) 

of the length of the hemisphere. 

b. Horizontal Distance, Superior End of Central to Parieto-occipital Fissure ^ 

Left Right 

Kishu.... 4.1 cm. or 22.8^, 4.0 cm. or 22.3 ^ 

of the length of the hemisphere. 
Nooktah.. 2.3 cm. or 13.7 ^, 3.5 cm. or 20 6 ^ 
^ of the length of the hemisphere. 

Anat. d. Centres Nerveux, Paris, 1895, p. 249. The coincidence of the relatively 
soniewhat small occipital with relatively small parietal lobes is quite curious. Gratiolet 
(quoted by Cunningham, p. 59) states that in man the occipital lobe is extremely re- 
duced ; and formulates the law that "the more highly organized a member of the 
group is, the smaller is the relative size of the occipital l.obe." Quite as striking, how- 
ever, is the small relative size of the parietal lobe in the ape. 

^ The measurements are taken between the points of intersection by the fissures of 
the superior border of the hemisphere. Where the parieto-occipital fissure bifurcated 
before reaching the superior border (left in Atana, right in Avia), the measurement 
was taken to a prolongation of the main limb of the fissure. Same with surface 
measurements. 



AN ESKIMO BRAIN 43 

Left Right 

Atana. , (5.1 cm. or 29.8 ^), (4.6 cm. or 26.9 ^) 

of the length of the hemisphere. 
Avia. . . . (4.0 cm. or 26.1 ^), (4.4 cm. or 28.8 ^) 

of the length of the hemisphere. 

c. Horizontal Distance^ Parieto-occipital Fisstire to Occipital Pole 
Left Right 

Kishu 3.0 cm. or 16.7 ^, 3.1 cm. or 17.3 ^ 

of the length of the hemisphere. 
Nooktah. 3.6 cm. or 21.4^, 2.8 cm. or 16.5 ^ 

of the length of the hemisphere. 
Atana. . . (2.4 cm. or 14.0 ^), (2.5 cm. or 14.6 ^) 

of the length of the hemisphere. 
Avia (1.5 cm. or 9.8^), (1.6 cm. or 10.5 ^) 

of the length of the hemisphere. 

These measurements show almost generally a higher relative 
proportion of the region between the central and parieto-occipital 
fissures than was the case with the surface measurements, which 
indicates that the region is relatively more flat than the others. 

Two more notable facts shown by both the arc and the hori- 
zontal measurements are a very small parietal and a large occipi- 
tal portion on the left in Nooktah and the small occipital portions 
in Avia. 

A more detailed study of the figures shows that, so far as 
their size is concerned, the main portions of the cerebrum tend to 
compensate each other. 

DISTANCE OF THE LOWER EXTREMITY OF THE CENTRAL FISSURE FROM 

THE FRONTAL POLE 

Cunningham measured this distance over the surface of the 
frontal lobe, comparing the dimension thus obtained with the entire 
arc running in the same line from the mesial border of the ante- 
rior to that of the posterior extremity of the hemisphere. I have 
followed the same method, but have supplemented it with the 
horizontal distance, as with the preceding measurements. The 
results are as follows : 



44 AN ESKIMO BRAIN 

Surface Distance of the Base of the Central Fissure fro?n the Mesial Border of 

the Anterior Extremity 

a. Arc to the base of central fissure. b. Complete lateral arc. Centesimal relation 

of a to b. 
Left Right Left Right Left Right 

Kishu.... 10.8 cm. ir.icm. 25.2 cm. 24.5 cm. 42.9 45.3 

Nooktah.. 10.7 cm. 10.5 cm. 23.3 cm. 23.1 cm. 45.9 45.5 

Atana.... (11.2 cm. 10.6 cm.) (22.9 cm. 23.1 cm.) (48.9 45.9) 

Avia ( 8.0cm. 8.6cm.) (21.3cm. 21.1 cm.) (376 40.8) 

The centesimal relation oi a to b is termed by Cunningham 
(p. 179) the lower Rolandic index and was: 

In 17 adult whites, males 43.7 

In 20 adult whites, females 43.0 

The index differed but little in children and human embryos ; 
in apes and monkeys it ranged (p. 175) from 39.2 in the orang and 
chimpanzee to 43.8 in cebus. 

The horizontal distance of the base of the central fissure from 
the frontal extremity, and its centesimal relations to the length 
of the hemisphere, are as follows : 

a. Distance to base of central fissure. Centesimal relation of a to 

length of hemisphere 
Left Right Left Right 

Kishu 7.3 cm. 6.5 cm. 40.6 ^i^.-^^ 

Nooktah 7.6 cm. 7.5 cm. 45.2 44.1 

Atana (8.3 cm. 7.8 cm.) (48.5 45.3) 

Avia (5-4 cm. 5.9 cm.) (35.3 38.6). 

LENGTH OF THE CENTRAL FISSURE 
a. Diameter, from lower to upper extremity, b. Length measured by a thread fol- 







taken by 


the sliding 


compass. 


lowing all the ■> 


ivindings of the fissure. 









entesimal relation of a 


to 


Centesimal reJ 


iation of b 








length of hemisphere. 






to mesial length. 




/. 


r. 


/. 


r. 


/; 


r. 


/. 


r. 


Kishu 


. 9.0 


8.6 


50.0 


48.0 


II. 7 


II-5 


43-0 


42.3 


Nooktah.. . 


. 8.0 


8.4 


47.6 


49-4 


10.7 


II.O 


42.6 


42.5 


Atana 


. (7.3 


7.7) 


(42.7 


44-9) 


(10.8 


10.6) 


(42.2 


42.7) 


Avia , 


.. (7.9 


7.7) 


(51-6 


50-3) 


(ii.o 


10.3) 


(45.8 


42.9) 



AN ESKIMO BRAIN 45 

Cunningham (p. 191), taking the length of the fissure accord- 
ing to b and comparing it with the mesial arc, obtained in whites : 

In 5I to 6^ mos. embryos 16.7 

In full-term foetuses 32,8 

In 4- to 5-year-old children 33.9 

In 16 adult females 40. i 

In 14 adult males t^Z.6 

and in the chimpanzee 51. i 

orang 47.2 

hamadryas 41.1 

The length of the fissure, as seen from the above, is relatively- 
greater in the Eskimo than in the whites ; there is no decided 
sexual difference. 

The straight length, or diameter, of the fissure can serve, in 
connection with the horizontal measures (from the vertical plane 
rising from the anterior extremity of the hemisphere to the two 
extremities of the fissure), in determining a Rolandic angle (by 
projection). 

LENGTH OF THE SYLVIAN 

Taking this length with a compass, from the exterior point of 
intersection of the Sylvian by the anterior or horizontal portion 
of the presylvian, to the angle which the ascending terminal 
branch forms with the main limb of the Sylvian, Eberstaller 
(quoting Cunningham) found it in whites as follows : 

Up to 5.0 era., left in 22 ^, right in 45 <fo of hemispheres. 

5.1-6.0 cm., left in 42 ^, right in 44 ^ of hemispheres. 

6.1-7.0 cm., left in 27 ^, right in 11 ^ of hemispheres. 

Over 7.0 cm., left in 9 ^, right in 0.6 <fo of hemispheres. 

These figures show that the left Sylvian is more often the 
longer. Cunningham (p. 122) obtained similar results, but he 
measured the fissure from *' the point at which its trunk appears 
on the outer surface of the hemisphere." As this point is almost 
generally less clearly defined than that employed by Eberstaller, 



46 



AN ESKIMO BRAIN 



I follow the latter authority. The Sylvians in the Eskimo 
measured as follows : 

Centesimal relation to the length of the 
hemisphere 

Left Right Left Right 

Kishu 6.5 5.2 36.1 22.9 

Nooktah 6.2 4.8 36.9 28.2 

Atana (6.4 5.1) (37.4 29.8) 

Avia (5.4 5.9) (35.3 38.6) 

The left fissure is, in three of the Eskimo, both absolutely and 
relatively, decidedly longer than the right one. 

Two additional useful and quite easy measures are, I think, 
the maximum breadth of the frontal lobes, measured by the 
sliding compass, with the branches applied over the most promi- 
nent points on the dorsum of the orbital parts of the inferior 
frontal gyri ; and a diameter between the extremities of the tem- 
poral and occipital lobes. These dimensions in the Eskimo are 
as follows : 

BREADTH OF THE FRONTAL LOBES 

Centesimal proportion to maximum 
Breadth width of the cerebrum 

Kishu II. 5 cm. 84.6 

Nooktah lo.o cm. 76.3 

Atana (7.9 cm.) 64.2 

Avia (7.5 cm.) 64.7 

These figures demonstrate well the superiority of the frontal 
lobes in Kishu's cerebrum, and the inferiority in this respect to 
both the males of both of the females. 

TEMPORO-OCCIPITAL LOBES 



Left 

Kishu 14.2 cm. 

Nooktah 13.2 cm. 

Atana (i3-i cm.) 

Avia (12.0 cm.) 



Centesimal relation to the length 
of the hemispheres 


Right • 


Left 


Right 


14.3 cm. 


78.9 


79-9 


13.5 cm. 


78.6 


79-4 


(13.4 cm.) 


(76.6) 


(784) 


(11. 7 cm.) 


(78.4) 


(76.5) 



AN ESKIMO BRAIN 4/ 

In this particular measurement the four brains show remarkable 
similarity. 

PREVIOUS RECORDS ON ESKIMO BRAINS 

The only previous records concerning Eskimo brains of which 
I could learn are those made by Chudzinski, published in the 
Bulletin de la Soci^te d' AntJiropologie de Paris ^ 1886. 

The brains described by this author were those of Tobias 
Ignatius, male, 23 years; Paulus Abraham, male, 35 years; and 
Ulrika Henocq, female, 24 years. The locality from which these 
subjects came is not stated, but there are reasons to believe that 
they belonged to the eastern Greenland Eskimo. 

The three brains present some interesting similarities, but also 
many characteristics different from those of any of the specimens 
noted in this paper. In order to facilitate a comparison I shall 
introduce the principal part of Chudzinski's report. 

The brains show '* a considerable volume of the cerebral hemi- 
spheres " ; " then one can see that the convolutions which con- 
stitute the external surface of the hemispheres are large, simple, 
and very poor in secondary divisions, and that the sinuosities are 
but little flexuous." " That simplicity is especially marked over 
the frontal lobes " ; ** the same lobes are at the same time 
flattened infero-superiorly." 

" The Sylvian fissure appears to be shorter than ordinarily, 
nearly horizontal, and of very simple contours," except in the 
woman, where it is little more complex, especially on the right. 
" Its anterior branch is generally very short and in the brain of 
P. A. altogether hidden by the temporal lobe." 

"• The Rolandic fissure is very long." " It is flexuous, espe- 
cially in P. A. Ends on mesial surface " (in all ?). 

" Occipital fissure very short externally. Calcarine fissure long 
and flexuous, especially in U. H." 

" The frontal lobe is relatively short ; the other lobes are, on 
the contrary, well developed, especially the parietal." 



48 AN ESKIMO BRAIN 

" The first frontal gyrus is very large, especially in Tobias, but 
shows only a few incisures." 

*' The development of the second convolution is enormous, 
especially in P. A." *' The gyrus is very simple in Tobias." 
**" Among other features, there is a double anastomosis with the 
ascending frontal." 

'' The third frontal gyrus is very little developed ; it is short 
and as ramassee siir elle memey " In Tobias it is reduced to a 
small, nearly smooth isle." Better developed in U. H. 

'' Ascending frontal gyrus very large." '^ Ascending parietal 
gyrus very flexuous in Paulus, very large in Tobias." The two 
gyri (asc. frontal and asc. parietal) are slender in U, H. 

" The parietal convolutions generally simple and very ex- 
tended," especially the second inferior. 

'' Occipital lobe generally simple, especially in Tobias." 

Temporal lobe : " Extreme slenderness of first convolution " ; 
" uncommon size of second convolution." 

Internal (mesial) surface : '' Enormous development in breadth 
of the mesial part of the first frontal convolution, especially in 
Tobias; a division of that convolution into two secondary gyri 
by an uninterrupted sulcus on the left hemisphere in Paulus." 
The secondary sulcus seems to be continuous with the subfrontal 
fissure. Similar sulcus on right in Paulus, but in several places 
interrupted by annectent gyri. 

The convolution of the corpus callosum is generally very ex- 
tended ; but its breadth is very remarkable in Tobias, in its pos- 
terior part, and anteriorly in Ulrika, in whom it seems to divide 
itself along its middle into two secondary gyri." 

The ovalaire lobule is enormous in Ulrika ; on the other hand, 
the cuneiform is small, and in Ulrika it is reduced to a '' pli de 
passage,'' hidden, in large part, in the calcarine and occipital 
fissures. 

The similarities in the brains reported upon by Chudzinski 
and the one described here consist of the large volume of the 



AN ESKIMO BRAIN 49 

cerebral hemispheres; long central fissures; sagittal division of 
the mesial parts of the superior frontal gyri ; the large size of the 
limbic lobe in Tobias, and the large size of the lobe with a ten- 
dency toward a longitudinal division in Ulrika. 

The dissimilarities are : the poor differentiation in Chudzinski's 
specimens of the convolutions and the simple character of the sulci, 
especially over the frontal lobes ; a defective development of the 
inferior frontal convolution (particularly in Tobias); very large 
ascending frontal and ascending parietal convolutions ; simplicity 
of parietal convolutions ; great slenderness of the superior temporal 
gyri ; and very small cuneus. 

The causes of the many dissimilarities are not clear. The 
morphological inferiority of the two male brains described by 
Chudzinski, and, on the other hand, the marked superiority of 
Kishu's and even of Nooktah's brain, may be to some extent 
individual conditions and represent more the extremes than the 
average of Eskimo'brains. At the same time it is possible that 
Paulus Abraham and Tobias Ignatius belonged to some family 
of the great Eskimo tribe intellectually less developed than the 
Smith Sound group to which Kishu and Nooktah belonged. The 
Smith Sound party which Lieutenant Peary brought to New 
York were by no means dull or incapable people. This is espe- 
cially well demonstrated in Menee, the son of Kishu, who has not 
only shown a remarkable facility for adjusting himself in every 
way to civilized life, but has made very good progress in the 
public school. 

The marked differences of the specimens described by Chud- 
zinski and in this paper from those of the whites, as well as 
among themselves, makes a future acquisition of Eskimo brains 
very desirable. 



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